Question: Solve for $p$ : $7 + p = 25$
Subtract $7$ from both sides: $ \begin{eqnarray} \\ 7 + p &=& 25 \\ \\ {-7} && {-7} \end{eqnarray} $ $ \begin{eqnarray} \hphantom{7 + p} &\hphantom{=}& \hphantom{25} \\ p &=& 25 {- 7} \\ \end{eqnarray} $ Simplify. $ p = 18$